Technical report on Harbour job in Cape Town
Construction of the Ground Anchor Beam:
The Ground Anchor Beam is an element that is 18m wide and contains the anchors that keep the old quay wall from moving away from the new quay wall. Anchors of approximately 36m, gets drilled into the old quay wall and the ground beneath it at an angle of 55°. The anchors get grouted up and stressed to a strength of 750kN.
The construction of the actual anchor beam consists of different parts. We start by breaking the old concrete nib with a big excavator with a monti-berd breaker. Then we excavate the old backfill and cut the extruding rebar. Next we backfill and compact to the correct level and cast blinding of 50mm thick. There after we erect the shutters and the steel fixing commences to a cover of 60mm all-round. After the steel fixing is complete and the stop-end is in we cast the beam with 45Mpa concrete.
This also involves planning, ordering of concrete, ordering reinforcing steel, conducting inspections etc.
Construction of the Anchor Beam – Deck Infill Slab
After both the Deck and Ground Anchor Beam has been cast and all the anchors have been installed, the construction of the infill slab between these two elements can start. This infill slab connects the deck insitu and ground anchor beam to each other to complete the new harbour quay wall.
Firstly, the gap between the deck and anchor beam needs to be cleaned and washed out. After the gap has been cleaned the transverse beam pockets needs to be filled with concrete to the desired level. When the pockets are completed the steel fixing can start. The reinforcement of the infill slab consists of reinforcing steel as well as glass fibre reinforcement. If both of these bars are inserted and fixed according to the drawings, the concrete can be cast.
Installation of the Landside and Seaside crane rails.
The crane rails carry the new Liebherr Container Cranes so it can move up and down the quay wall to the berthed container ships. These crane rails are A120 rails, which is the biggest type of crane rail in the world, and gets imported from Sweden.
Firstly we remove the old crane rails, which used to carry the old cranes, with a excavator and breaker. Then we set out the positions of the holding down bolts which will be grouted in. The positions get set out with a total station and a template. The core drillers drill holes in the concrete for the bolts and it gets grouted in position. The nuts of the holding down bolts get levelled to the correct height and the sole plates get placed on top of the levelled nuts. After the sole plates are placed, levelled and fastened, the crane rails get stacked on top of the sole plates and welded to each other in a straight line. If the welds passed the tests, the welds can be grinded smoothly at the top and bottom.
The alignment of the crane rails can now begin. Rubber pads get placed underneath the rail to decrease the vibration of the cranes on the rail and grout. Rail clips are inserted and used to align the crane rail to a tolerance of 1mm over 2m. After the alignment is done the grouting underneath the sole plates can start. Grout get mixed and poured underneath the soleplates to ensure the load get transferred equally.
In this past year I gained experience in various parts of the construction environment. I obtained practical and theoretical knowledge which will assist me in the coming years of studying and working. This practical year ensured that I will be well prepared when entering the construction environment after I finished my studies.
While working, I also improved my communication skills and learned how to work together in a team. These skills help me to communicate effectively in an engineering environment and to motivate team members successfully. Furthermore I obtained problem solving skills and learnt how to co-ordinate projects and activities. This year’s work also helped me to improve my safety awareness and to understand how important safety is in the engineering environment.
My opinion is that this experiential learning year will help other students to also obtain the above mentioned skills in the future. I think this year prepares the students well for the future and to become good engineers one day.
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